Relay commutator



April 16, 1929. PRUDEN 1,708,955

' RELAY COMMUTATOR Filed Sept. 11, 1926 Wenfan Harald/ f. Pruden .i tpro Mi, 192th lEclltlEUltAtTtllEi/IEE, THEE.

llRMOLD lift. PlltlJDIEN, 015 "WYUMING, 3's

INGDRI URATED, til."

means Applieaticafilec. fiepteinizier 11, 19556. aerial Itl'c. rat-sea.

This invention relates to telephone tems and more particularly to the provision ct improved commutation; means .i'or signat ing current generators.

in accordance With the present invention the distribution of signaling current to ditlercnt portions ol the operating; circuit is accomplished by the use oil a relay commutator comprising a pair of single Contact polarised relays controlled from a source out loiv trequency alternating current. The current generator is associated with an outgoing circuit having aplurality of branches by means oi a transformer having a plurality of outpu t windings. The relays connect pairs oi output windings in series to alternately short circuit the branches of the outgoing circuit in. order to provide interrupted signaling current to one branch at a time and to maintain the impedance balance in other branches.

it clearer conception oi? the aspects of the present invention may be had from theiollowing description and attached drawing.

The invention is described and shownas embodied in a system for providing voice frequency signaling current in toll switching 1 systems and in connection With a mechanical oscillator for generating voice til'cqucncy cur-- rent of the type disclosed in the application of l5. i /eise, tlerial No. 91,201.,i'tilsd liebruary 27., 1926. V i i i This type of oscillator is composed of a mechanically tuned reed 136 supported at two points 181 and 132 and vibrating between two carbon buttons 1% and 1.35. The reed 1456 is caused to vibrate at its natural trequency by an electromagnet 130 and a carbon button 133 located. at the center of the reed. ln order to prolong the life of the carbon. buttons a start relay is sod which. is controlled by the signaling; key at any operators position. y

ill hen ground is connected to start leadv 120, relay 105 operates over a circuit including contacts of jacks l0]; and 102 or jacl's 103 and 10 i and closes a circuit from battery on its upper trout contact, back contact of relay 1G6, Winding 0t magnet 130 to ground. through carbon button 133. The current in this circuit deflects bar 136 strongly in order to insure the starting]; of the vibrator. 'lhe circuit also extends throughstarting impulse relay 106 to ground, but as relay 106 is slow to operate, the circuit for magnet 130 traced above is maintained momentarily and is then and lilo orcrfct siiiddeu reduction current through the viii itor magnet permit tiN-r reed. 138 to start oscillatirur". 'f..he o co ation oiirelay 1.05 also closes a circuit ior polarised relays lili and. 1.08 :troln low frequency source 109 throiurh lamp 11.0, lower trout cru tact of relay 105., windings of relayslfi'i' and M8, baclr to source 109. As on these relays are polarised tli y operate dun ing; one hal oi. each cycle of current and release during}; the other half cycle. lii hen these relays are normal a circuit closed from coinluctor 122., tip contacts ct iacl-is lill 7c and 1052, middle \Vll'lLilll,'-,I oil transformer it bac contact elf relay 1033 right Winding ct transforiner 3115i, ring contacts ct jacks 102 and 101 to conductor 1%. It? the same time a shunt is connected across conductors 19A: 7; and 12.5 over a circui iii-om ceudurtor i acks 103 a weir contact ct relay I tip co. .tuc (F; 1041; and 103. i ii hen relays 107 and we ope 9 a siniut is connecteo across condrmtim; .l/JZ and i223 so traced throiurh the trout contact of re ay lift and current is couuecied to conductors till tip contact winding: of relay. 10?, 11s to u The cu TiMlransi or icr 118 is thereby alternately. co nected. :filbu b0 one set oi iaclis and a shunt is placed a the other and then to th "her set oi jacus while the ii. i; is shunted he substitution elf this shunt the si a ling); l'i'llicliftill' scrves to maintain the impedance balance rlieuv using repeaters and thus .iiuo rues the opcraticirot the toll signaling. is arr: there ire provides interrluited sin alien current to a plurality ottoll lines while niaintainiiug the impedance during; the silent periodf it also short circuits any noise current, which may be present on on toll line and which might naslr the silnt period, thereby preventing its tlttllSIlllSk on to other toll lines to which signal currents are siniultaueously being supplied over the same signaling conductors.

'lhe pair of jacks, for example 101 and 102 in conjunction with suitable patching; cords, permit variation of the interconnection oi? signaling circuits and si ealing sources. Jack 102, for example, peri'nlts supplying current ed through the sleeve of jack such as 101, the

sleeve conductor of the patching cord, the sleeve of jack 102 to the winding of relay 105.

Rheostat 116 is provided to control the potential of the output current from trans former 118 by adjusting the direct current flow through the'earbon buttons 134tand 135.

Thevoltmeter key 113 and the voltmeter 112 are used for checking the amount of output current from the middle winding of transformer 118. As the right and middle windings of transformer 118 have the same electric'al characteristics and are connected in series when used .in the circuit, the reading on the voltmeter 112 will. be one-half the output potential. When the voltmeter key 113 is operated, ground on its lower contact is connected to the. start lead through relay 105, thereby causing the circuit to function as has been described above. 7

While the invention has been disclosed in connection with tool telephone systems, it ma y be applied to other types of signaling systems.

VVhat is claimed is:

1. A system comprising a source of current,

' a circuit having a plurality of equivalent branches, means for coupling said source to said circuit, electromagnetic means for a ternately 'short-circuiting certain of said branches whileconneeting said source to the remainder of said branches and connecting said source to said certain of said branches While short-circuiting the said remainder of said branches, and a separate source of current for intermittently operating said electromagnetic means.

2. A telephone system comprising a source of current, a circuit having a plurality of equivalent branches, electromagnetic means for alternately coupling said source to half of said plurality of branches and simultaneously short-circuiting the other half of said branches, and a source of current of a different character for operating said electromagnetic means.

3. A system comprising a source of current, a circuit having a plurality of equivalent branches, electromagnetic means, a control circuit for energizing said means to alternately couple and short-circuit said source of current with relation to said plurality of branches, and a separate source of current for energizing said means.

4:. In a system comprising a source of current, a circuit having a plurality of branches, a transformer for coupling said source of current to said circuit, said transformer having a single input winding and a plurality of output windings, one output winding connected to one side of all of the branches of said circuit and the other output winding connected to the other side of. all of the branches of said circuit, and a pair of polarized relays for connecting said output windings in series in opposite directions to supply signaling current alternately to the branches of said cir cuit.

5. In a system comprising a source of current, a circuit having a plurality of equivalent l'n'anches, means for coupling said source to said circuit, olectron'iagnetic relays, a sepa- -ate source of alternating current for intermittently operating said relays, said relays serving to control said coupling means to intermittently couple said source to one of the branches of said circuit and to short-circuit the remainder of said branches.

6. In a signalling system, a source of signalling current, a transformer having a primary winding connected to said source of current and :1 pair of secondary windings, two load circuits connected to the terminals of said secondary windings, a relay for mch load circuit, each relay having an armature and contact arranged to short-circuit its associated load circuit and means to periodically operate said relays to alternately short-circuit each of said load circuits, whereby signalling; current is alternately supplied over the other of said load circuits.

In witness whereof, I hereunto subscribe my name this 8th day of September A. 1)., 192-6.

HAROLD M. PB U DEN. 

